Car Stutters and Jerks...Faulty Sensor?

[Nisko]

I was unfortunately daft enough to go in to a service station to have a high pressure engine wash done on  my 2010 1.6 petrol Fabia over a long long holiday weekend. The compulsion to 'constructively' use ones time off has a lot to answer for!

Anyhew, got a fairly clean engine bay back, but though the car cranked up and slid out of the wash area normally, all hell broke loose soon after. 

It stalled, I restarted, it was having none of it. A few cranks later, it eventually started with the Rev count permanently situated at 1000 rpm without coming down. It simply stayed there. 

Thoroughly ticked off but on some alternate universe overjoyed it was at least motorable, I paid and left suspecting water had gotten in to plugs or somewhere else it had no business but  would eventually dry out. I surmised the unusual rev count was the cars smart way of coping in order to keep itself going, and that it would return to normal by the following day. So I kept my OCD in check, eventually got home and tried not to think about it. 

Sure enough, next day car was back in sinus rhythm. But once I tried to drive out, splutter, misfires and jerking ensued. Was still confident the engine simply needed drying out, or a plug or two needed replacing, called up mechanic and headed in. 

As suspected a plug was changed as it had died (the darn pressure wash being the cause evidenced by a little water around the chamber), car calmed down. We ran another diagnostic after the initial one telling us there was a misfire in 1 and 2 as it's idle was better, but it still hiccupped and jerked when pulling away or whilst driving up an incline rapidly. 

The new error code is P0327 knock sensor low circuit output bank 1, and it won't be denied. It wants my attention, and it's definitely gotten it as I hate driving the car now. 

The occasional jerk and wobble reminds me every time I  caused this with the bloody high pressure wash. Never again! 

I live in the tropics by the way. Daytime temperatures hit 37 Celsius easy, and though we are in the rains at the moment, think it's safe to say drying out is no longer the issue. 

Mechanic says I should change coil packs, the lot of them. Fine for him to say, he isn't paying the bill! They are expensive, especially here, where it's not exactly a common brand. In fairness to him though, his cheapest alternative advice is that we do nothing. That the  car will balance out, and will go back to normal. OCD me has however long since been replaced with Manic mode me. Too far gone up the road of  'I hate this!' to now do nothing.... 

Anyway, tested by earthing, the coils and plugs all seem to be working OK, and the diagnostic reader no longer brings up faults of misfires in any of the chambers. 

Having done some reading online, realise the P0327 could be as a result of the high pressure water dislodging a wire, or at least something less dramatic than the need for a total coil pack change or the replacement of the sensor itself. 

The sensor seems like a totally complicated piece of kit, so much so the mechanic doesn't even  know where it is on my car. He looked. 

So one of my questions is where is it on a Fabia mark 2. Diagram and or pics would be incredibly helpful, so one can check for connections and wiring that might be dislocated.

Another is how much and where might I get it online if I am (hopefully not) forced to replace. And how complicated is it to fix the replacement part? What I read so far has me believing I might first need a crash course in automotive engineering and that just to properly supervise...I need help! 

 

Thanks in advance, and my sincerest apologies for the amount of words you just waded through. 

Would just really like my car back to where it ran without its new affectations. 

[mrgf]

Hi Nisko, Whilst I would agree with you that you inadvertently "Caused" This issue, I think drying out is not the problem but one of clinically cleaning said sensor or whatever electronic/electric gremlin you may have... I am in a hurry now but can try looking in my Haynes manual later today, if this helps. That said, I think a very goos starting point is to OBTAIN a copy of the Haynes manual, if possible as they are pretty much considered a necessity over here in the rainy country. (England). You might find an alternative but Haynes are the industry standard! I believe America or someone else produce Climer Manuals, at least for motorcycles but Haynes is the better known for cars.

[Nisko]

Hi mrgf and thank you for your response and the heads up on the Haynes.

Not to sound lazy, but your kind offer to look up the manual would be helpful and greatly appreciated. Very much doubt I'll be able to lay my hands on one. 

The gremlin must be banished. 

Edited 19 June, 2018 by Nisko

[mrgf]

About to have a little look in the book but whilst I do that, have you tried simply taking off the battery for ten-fifteen mins, reconnecting it and then going for a drive for about twenty mins, with varying revs, gears, etc? You would be amazed at how often that "Cures" the odd hiccup!

[mrgf]

OK, Knock sensor, petrol engines, Extracted from Haynes...

This sensor is located on the rear of the cylinder block, below the inlet manifold and appears a bit tricky to get access to. You will need to take off the plastic engine cover, locate the sensor and disconnect its wiring. Alternatively, follow the wiring and disconnect from the wiring connector. It also suggests to make it easier, you remove the inlet manifold, if you are able to. This will allow easier access to the sensor.

 

The next option is to go in from the underside and again, access will be greater if you can remove the right hand driveshaft. Be sure to secure the vehicle properly as you will need to jack it up for this method and use axle stands/chocks etc to make things safe. To remove sensor, unscrew its mounting bolt, removing the sensor from the block, noting its fitted position. Refitting is the reversal of removal, taking care to ensure both the sensor and the block are clean and dry and that you tighten it to the correct torque! This will ensure correct operation.

 

Just by finding the location, though, your mechanic might be up to the job for you here. I would assume either replacing or renewing the sensor, depending on cost.

 

Haynes manuals are available online from;      www.haynes.co.uk   and the ISBN number for this manual is ISBN 978 1 78521 033 4    The manual number is 6033 Skoda Fabia (May 2007 to 2014) Covering both petrol and diesel. Hope this helps...

Edited 19 June, 2018 by mrgf

[mrgf]

Nisko, i have just re-looked at the Haynes manual rear cover and it states "Does not cover 1.6 petrol engines" Along with the VRS, Scout etc or automatic transmission either... Mostly as they are more specialist stuff but even without the exact specs, many things WILL be the same. It is most likely the sensor will be inn or abound the same area and may still be a great help as a manual, despite not being specific. 

 

I hope i have not sent you off on a wild goose chase and hopefully someone else can either back up or correct any information I have tried to provide... 

Edited 19 June, 2018 by mrgf

[Nisko]

Hello mrgf! 

Wow and many many thanks for all the information and your time...

Wild goose chase - No, you haven't. Though mine is an auto, I'm sure you presume correctly that essentially, much will appear the same with the location of the sensor with my car. 

 

Update... 

Drove to work yesterday and had the very barest of stutters on my way in. The homeward journey however was a totally different experience...not even a murmur! Couldn't be more pleased to report, car behaved itself- not a hint of the annoying problem. 

I thanked the heavens with relief once back home,  and have everything crossed this was what my mechanic referred to as the car finally balancing out and running back to normal on its own.

Will see how it goes today, and definitely prefer the option of removing the battery head as suggested should I run into any further problems. The locating, cleaning and or replacement of the sensor as stated from Haynes gives me a headache simply from reading.  Can't imagine I'd have much hair left on me were the mechanic to actially attempt the 'procedure'. 

Once again, many thanks and will be sure to give another update in a day or two. 

[Ootohere]

Sorry might have missed it reading on the phone, but was the airbox opened and the air filter checked to see if wet?

[Nisko]

Actually Offski, no and no (airbox opened, filter checked), and no you didn't miss it.... 

Interesting pointer. 

Thank you for your suggestion mate.